# Author:sp
# CreaTime: $(DATE)
# FileName: $(NAME)
# Description: simple introdution of the code
class Instrumnet():
    def make_sound(self):
        print('乐器在演奏')
class Erhu(Instrumnet):
    def make_sound(self):
        print('二胡在演奏')
class Pinao(Instrumnet):
    def make_sound(self):
        print('钢琴在演奏')
class Vilolin(Instrumnet):
    def make_sound(self):
        print('小提琴在演奏')
class bird():
    def make_sound(self):
        print('鸟在叫')
def play(mu):                    #多态，动态语言
    mu.make_sound()

if __name__=='__main__':
    play(Instrumnet())
    play(Erhu())
    play(Pinao())
    play(Vilolin())
    play(bird())

